6-2 Forest Biomes

Tropical Rain Forests

Tropical Rain Forests Characteristics: High humidity 200-400 cm rainfall/year (400 inches) Warm, constant temperature year-round Greatest specie diversity (half world’s specie) Poor soil Near equator Helps regulate world climate & mineral cycles

Tropical Rain Forest Nutrients: Decay is rapid Uptake by plants is rapid for quick growth Soil is poor in nutrients

Tropical Rain Forest Layers: Plants adapted to growing in layers & to different amounts of sunlight Emergent layer – top layer grows in direct sun Canopy layer – gets 95% of sunlight. Primary layer – most animals live here Understory – little light, adapted to shade (source of house plants) large flat leaves

Leaf adaptations

Tropical Rain Forest Threats: Used to occupy 20% of Earth’s surface Today occupies 7% of Earth’s surface 100 acres/minute/day lost to logging, agriculture, oil exploration Results in habitat destruction & loss of biodiversity (also exotic plant & animal export)

Temperate Forests Two kinds: Temperate Rain Forests Temperate Deciduous Forests

Temperate Rain Forests Found along the northwest coast of the US (N. California, Washington, Oregon), the mountains of North Carolina, Australia, and New Zealand.

Temperate Rain Forest Large amounts of precipitation High humidity Moderate temperatures Dominate trees in northwest are evergreens 90 m tall – Sitka spruce, Douglas fir, hemlock Mosses and ferns cover forest floor

Temperate Deciduous Forest

Temperate Deciduous Forest

Temperate Deciduous Forest Eastern Us, Europe, Asia Located between 30 – 50 degrees north latitude Broadleaf trees that change color and lose their leaves in fall Wide range of temperatures, seasons (4) Decomposition slower than rain forest, so soil is richer

Temperate Deciduous Forest Animals: adapted to use forest plants for food and shelter Birds are migratory.

Temperate Deciduous Forest Plants: dominate trees maple oak birch

Temperate Deciduous Forest Plants are adapted to seasonal change

Taiga

Taiga Northern coniferous forest below arctic circle. Long winters (6-10months). Summers have constant daylight Average temperature below freezing Plant growth most abundant during summer Permafrost – ground frozen year round, top part thaws in summer

Taiga Plants: Conifers: needle-like leaves with waxy covering to prevent water loss Shape of tree (cone shape) helps trees shed snow without breaking branches

Taiga Soil – acidic from decay of needles. Plants & bacteria do not like acidic soil Decomposition slow Little plant variety

Taiga Animals: Many waterfowl (lots of lakes & marshes) Birds migrate south in winter Food scarce, many animals burrow & hibernate Some animals (snowshoe hare) shed brown fur & grow white fur for camouflage